Skin, which is the body's first line of defense against disease, acts as a protective barrier for the body, and the epidermis serves as a barrier against invading microorganisms. Accordingly, the primary purpose in the treatment of cuts, burns, abrasions, and other injuries to the skin, which are also referred to as wounds, is rapid closure and wound healing to prevent infection.
Wound healing clinically means that the skin is completely closed, and it is a complex process controlled by the interaction of many kinds of cells (e.g., keratinocytes, fibroblasts, endothelial cells, macrophages, platelets, etc.) (Sorg et al., European Surgical Research, 2017; Gonzalez et al., An Bras Dermato, 2016). Each process is controlled by a complex signaling network regulated by many growth factors, cytokines, and chemokines.
In general, wound healing is a complex process which occurs in three stages (i.e., inflammation, proliferation, and remodeling) (Grazul-Bilska et al., Drugs of Today 39, 2003). The first stage involves clotting to achieve hemostasis, supplementation of neutrophils to destroy bacteria and necrotic tissue, and subsequent supplementation of macrophages. During the second stage, angiogenesis occurs, and the endothelial cells enter the wound site, and simultaneously, fibroblasts enter the wound site and help to produce granulation tissue. The formation of granulation tissue causes re-epithelialization to occur. During the final stage, the levels of collagen production and destruction equalize, and the wound healed slowly changes to achieve maximum strength. Wound healing is delayed or damaged when any one of these stages does not function properly or in a timely manner. This can cause the wound to become a chronic wound, which is not only important to individuals but also can be a costly clinical problem. Accordingly, compositions that can accelerate the natural processes of the body that regenerate the skin and epidermal tissue are needed.
Meanwhile, ginseng contains various kinds of ginsenosides (e.g., panaxadiol ginsenosides (PD), panaxatriol ginsenosides (PT), oleanane ginsenosides, etc.) and gypenosides. The functions of ginsenosides (e.g., enhancement of immune function, excitatory action in the central nervous system, stimulation of secretion of adrenocorticotropic hormone, inhibition of platelet aggregation, etc.) vary depending on the kind, and thus, it is difficult to predict whether a ginsenoside of the same kind may have the same effect.
Under the circumstances, the present inventors have confirmed that gypenoside 75 (gypenoside LXXV) is involved in the migration and proliferation of keratinocytes and exhibits a wound healing effect in a mouse model, thereby completing the present invention.